How to keep kids from "Hanging out" after school

Many parents of junior and senior high kids, worry about what their children are getting into in the hours after school is out and before they get home from work.

What if school started at 10.00 am and went til 5.00. Those kids that are alone between 3 and 5 would now be alone between 8 and 10. Those hours could be used for extra curricular and sports activities, by the school and those children who aren't involved in these activities, i.e. have too much free time on their hands, would more than likely spend those hours sleeping. Kids just aren't going to get up early so they can "go hang out". I think this might put many parent's minds at ease.